I have a 1992 Mercury 115. When it is running (seemingly) proper it will push my boat 36 mph, but occasisionally it will only push my boat to 31 mph (even with the same water conditions). Also, when it is acting up it takes much longer to get on plane, even struggling to get there. The odd thing is it only acts this way ocassionally. It does this about every fifth time I put it on the water.
I have a water separator and it has been emptied.
It has fresh gas and oil.
For the life of me, I cannot figure out what the deal. Any ideas?
I think it’s in your ignition system DC. That motor should be pushing that boat a lot faster then even 36mph. I top out at about 50mph with same motor and a heavier boat.
Russ B.
God is great, Beer is good, People are crazy
I have a manual that describes the ignition system testing procedure pretty good DC, give me a shout after the 1st when I’m back in town and we can take a look at it.
Russ B.
God is great, Beer is good, People are crazy
the carb test is pretty easy, if you can duplicate the failure, while its failing, give the engine a shot of starting fluid into each carb one at a time, and if the engine picks up, its starving for fuel, if it bogs down, its functioning properly.
Pretty simple unit, I used to have one I made up but not sure if I still have it or not. Can also try swappin coils around. There are other tests for the coils, trigger and stator that just require a ohm meter that one can do first. I’ll be back to SC this weekend.
BTW, That wild game dinner worked out awesome!
Russ B.
God is great, Beer is good, People are crazy
just get going wide open with a buddy and start pulling plug wires wichever one does not change is the bad coil kind of dangerous but it worked for me i had the same problem on a pontoon
russ
how would you go about using a dva meter to test a coil that could be failing under load?
also, doesnt the coil put out well over 50,000 volts?
same science behind the TASER guns:)
DROPN
the test you are talking about we call a drop cylinder test, and it works great to isolate the weak cylinder, but it wont tell you if its fuel or spark related.
if the cylinder that doesnt change is running without fuel, the same thing would happen as if it didnt have spark.
Recommending the induction of Starter Fluid into an outboard to someone not familiar with the hazards of such “TESTS” is troublesome! I know, you know what’s up, but others may not be so sure?
I know how a DVA works, I was wondering how you actually applied the dva meter to the motor at WOT to use it, without death or dismemberment occuring.
it was a logistics question, not a science one
